Things went horribly wrong for the four men who tried to hold up a Harlem restaurant-supply shop on Thursday afternoon… The four men burst into Kaplan Bros. Blue Flame Corp. around 3:00 p.m. and things went downhill quickly for them:

“I’d do it again if I had to.”

Those were the first defiant words out of no-nonsense businessman Charles Augusto Jr.’s mouth yesterday as he came back to work less than 24 hours after opening fire with his trusty shotgun on four robbers — killing two of them.

The four men had picked the wrong shop — and the wrong man — to mess with. And they would have known it had they read the prophetic words from Dante’s “Divine Comedy” written in marker above the door: “Abandon all hope all ye who enter here.”

The thugs entered a world of hurt when they barged into Augusto’s Harlem restaurant-supply shop, Kaplan Bros. Blue Flame Corp., Thursday afternoon, pulling out a 9mm pistol and pistol-whipping an employee as they demanded cash.

“I told them there wasn’t any money. ‘Take your gun, put it in your pocket, and go home.’ They had a chance to leave,” Augusto said.

But they didn’t listen.

So Augusto, 72 — known to most as “Gus” — channeled his inner Dirty Harry and pulled out the Remington shotgun he had hidden under his desk for 20 years. He opened fire three times, peppering all four men with buckshot.

“I did what I had to do,” he said. “It wasn’t my choice; it was their choice.”

The wounded men tried to run but didn’t make it far.

The man armed with the pistol, 29-year-old James Morgan — who had a long rap sheet with nine prior arrests — took the first shot directly to his face and made it only as far as the shop door before crumpling dead to the ground.

A second man, Raylin Footman, 21 — who had a prior arrest for robbery and a relative who was a cop — made it across 125th Street before collapsing. He’d died by the time he was taken to a hospital.

Good shooting, Gus.

I wonder how long it be before the usual suspects show up and start protesting this guy for protecting himself and his employees?